Keypads are generally positioned on the exterior of a vehicle and are used to lock and unlock the vehicle, among other features. The driver may unlock the door in response to successfully inputting a factory code on the keypad, which is a code including a sequence of numbers or other such characters. The driver may also use the factory code to program a new code, sometimes referred to as a personalized code, which may be easier to remember than the factory code and usable to unlock the vehicle with the keypad.
Such keypads allow the driver to unlock and lock the vehicle without the use of a key. Generally, the keypad is electrically coupled to an electronic controller. The controller controls a mechanism to unlock and lock the vehicle in response to the factory code inputted by the driver via the keypad. Other such keyless entry systems may include remote frequency based transmitters operably coupled to the electronic controller. The electronic controller is configured to unlock and lock the doors of the vehicle in response to receiving radio frequency (RF) encoded signals from the transmitters.